For various reasons, the corneal portions of eyes must be surgically repaired or replaced. For example, the cornea may become scratched or scarred or otherwise physically damaged, greatly hindering sight. The cornea is also subject to the effects of various degenerative diseases, mandating replacement if the patient is to have normal or even near normal vision. Corneal transplants have become quite common in the United States, particularly with the advent of microsurgery. Unfortunately, donor corneas are very difficult to obtain. A cornea to be donated must be employed, if at all, within a matter of days or weeks from the time of death of the donor. Although eye banks have been organized throughout the United States, one cannot rely upon the availability of a donor at the time it is needed for a transplant opera tion. As a result, vision, which could have been wholly or partially restored in many patients, is often permanently lost. Furthermore, some diseases are not amenable to standard corneal transplants, and corneal transplants carry the constant risk of transmission of diseases carried in the transplanted tissue, including leukemia, syphilis, and Acquired Immunodeficiency Syndrome (AIDS). See Fuji Kawa, et. al., "Human T-Cell Leukemia/Lymphotrophic Virus Type III in the Conjunctival Epithelium of Patient with AIDS," 100 Amer. J. Opthal. 507 (October 1985); Pepose et. al., "The Impact of the AIDS Epidemic on Corneal Transplan tation," 100 Amer. J. Opthal. 610 (October 1985).
Attempts have been made in the past to utilize artificial materials for corneal transplants. Representative of such attempts are those reported in Barraquer, Queratomileusis y Queraqofaquia, Instituto Barraquer de America Bogata, Col. (1980); U.S. Pat. No. 3,945,054, issued Mar. 23, 1976, Fedorov, et. al., "Through Corneal Prosthesis and Method of In stalling Same"; and U.S. Pat. No. 3,458,870, issued Aug. 5, 1969, W. Stone, Jr., "Artificial Corneal Implants Having a Removable Lens Member."
For the most part, the implantation of artificial corneal materials has been at best a temporary stop-gap measure taken to seal the anterior chamber of the eye for a period of time until a donor cornea could be located for transplantation. As with other parts of the human body, the eye tends to reject and eject or extrude foreign materials during the healing process, with the result that the implantation of artificial corneas generally leads to loss by extrusion of the device, with further eye damage and leakage of aqueous humor from the anterior chamber. Attempts to affix artificial corneas to the cornea by adhesive typically fail because the living cells contacted by adhesive eventually die and slough off (necrosis), destroyinq the adhesive seal. Thus, the prior art devices have relied on elaborate mechanical attachment methods which are fraught with continued need for surgical revision, and have had short lived, limited success.